锌铋合金电极在溶胶电解液中的电化学行为

锌电极的自腐蚀速率, 持续放电下的阳极溶解速率和电极钝化的难易程度是碱性电池性能的重要电化学参数. 本文应用线性极化、恒流放电等电化学实验方法研究了电解液中添加Carbopol树脂以及电极中添加Bi对锌电极电化学行为的影响. 并应用金相显微镜和环境扫描电子显微镜(ESEM)对锌电极和锌铋合金电极浸蚀及放电后的形貌进行了表征. 结果表明: 电解液中添加适量的Carbopol树脂可明显提高电极的极化电阻, 显著降低电极的自腐蚀速率; 阳极的溶解电位出现不同程度的正移, 阳极过电位显著增大且大电流密度放电时较明显促进电极钝化. 锌电极中添加一定量的Bi对改善电极表面氧化物膜的沉积形貌和电极表面固液界面的传质条件, 减小电极的自腐蚀速率, 抑制电极自腐蚀等方面具有显著作用.

Electrochemical Behavior of Zinc-Bismuth Alloy Electrodes in Gelled Electrolytes

The self-corrosion rate, anodic dissolution rate, and passivating tendency of a zinc anode are important parameters that affect the performance of alkaline batteries. Effects of the addition of Carbopol resin to the electrolyte and the addition of passivation Bi passivation to the electrodes on the electrochemical behavior of Zn electrodes were investigated by linear polarization and chronopotentiometry. Surface morphologies of Zn electrodes and Zn-Bi alloy electrodes after etched and constant current dissolution were examined using a metallographic microscope and environmental scanning electron microscope (ESEM). Results showed that the addition of Carbopol resin significantly enhanced the polarization resistance, decreased the self-corrosion current, led to a positive shift in anodic dissolution potential, remarkably increased the anodic overpotential and promoted the passivation of alloy electrodes. The addition of Bi markedly improved the oxide film morphology and mass transfer between solid-liquid interfaces, decreased the self-corrosion rate of Zn electrodes and inhibited the self-corrosion process in Zn electrodes.